Growth hormone is a secretory protein of the pituitary gland of animals having wide ranging developmental effects on the organism. Artificial manipulation of growth hormone levels has been demonstrated to have significant therapeutic utility. Human growth hormone supplementation has been shown to be an effective treatment for growth hormone deficiencies and their related disease states in humans. Apart from this application, studies have uncovered new and significant properties of growth hormone which lend further importance to the ability to control growth hormone levels. For example, recent clinical studies indicate that growth hormone supplementation may be useful in combating the maladies of aging in humans. Elevated growth hormone levels in animals have been shown to result in increased lean muscle mass. One application of this latter observation could result in higher production of leaner meat products or in the production of larger and/or stronger animals.
While growth hormone is naturally produced by the pituitary gland, the secretion of growth hormone into the bloodstream is controlled by a second protein, Growth Hormone Releasing Factor (GRF). This hormone is also commonly known in the art as somatocrinin, Growth Hormone Releasing Hormone (GHRH), and Growth Releasing Hormone (GRH).
There are two ways to approach the problem of increasing circulating levels of growth hormone: (1) increase the level of human growth hormone in the organism directly or (2) increase the organism""s natural tendency to produce growth hormone. The latter strategy may be achieved via supplementation with GRF. GRF has been demonstrated to increase the circulatory levels of growth hormone in vivo. (Rivier, et al., Nature (London), 300:276 (1982). The effect of GRF, including structural analogs thereof, on growth hormone production has been widely studied. A primary obstacle to the use of GRF as a direct supplement is its short lifespan in vivo. L. A. Frohman, et al., Journal of Clinical Investigation, 78:906 (1986). More potent and/or longer lasting GRF molecules are therefore desirable for the development of effective human therapeutic or animal husbandry agents.
The structure of GRF has been modified in numerous ways resulting in longer lasting and/or more potent GRF analogs. It has been demonstrated that the first 29 amino acids from the N-terminus are sufficient to retain full GRF activity. Speiss, et al., Biochemistry, 21:6037 (1982). One strategy has been the incorporation of novel D-amino acid residues in various regions of the GRF molecule. V. A. Lance, et al., Biochemical and Biophysical Research Communications, 119:265 (1984); D. H. Coy, et al., Peptides, 8(suppl. 1):49 (1986). Another strategy has modified the peptide backbone of GRF by the incorporation of peptide bond isosteres in the N-terminal region. D. Tourwe, Janssen. Chim. Acta, 3:3 (1985); S. J. Hocart, et al., Journal of Medicinal Chemistry, 33:1954-58 (1990). A series of very active analogs of GHRH is described in European Patent Publication 511,003, published Oct. 28, 1992.
In addition to the actions of GHRH there are various ways known to release growth hormone. For example, chemicals such as arginine, L-3,4-dihydroxyphenylalanine (L-DOPA), glucagon, vasopressin, and insulin-induced hypoglycemia, as well as activities such as sleep and exercise, indirectly cause growth hormone to be released from the pituitary by acting in some fashion on the hypothalamus, perhaps either to decrease somatostatin secretion or to increase the secretion of GHRH.
In cases where increased levels of growth hormone are desired, the problem has generally been solved by providing exogenous growth hormone or by administering GHRH, or a related peptidyl compounds which stimulates growth hormone production or release. In either instance the peptidyl nature of the compound has necessitated that it be administered by injection.
Other compounds have been developed which stimulate the release of endogenous growth hormone, such as analogous peptidyl compounds related to GHRH. These peptides, while considerably smaller than growth hormones are still susceptible to metabolic instability.
Administration of the hexapeptide growth hormone releasing peptide-6 (GHRP-6) results in the secretion of growth hormone in many species, including humans. This peptide is one of a series of synthetic peptides, the structures of which were based on the pentapeptide Met-enkephalin. It has been shown that GHRP binds specifically to the pituitary, although the binding does not involve the opioid, GHRH, or the somatostatin receptors.
In recent years significant efforts have been taken to develop nonpeptidyl analogs of this series of compounds. Such compounds, termed growth hormone secretagogues, should be orally bioavailable, induce the production or release of growth hormone, and act in concert, or synergistically with GHRH.
Representative growth hormone secretagogues are disclosed in U.S. Pat. Nos. 3,239,345; 4,036,979; 4,411,890; 5,206,235; 5,248,841; 5,310,737; 5,310,017; European Patent Publication 144,230; European Patent Publication 513,974; Patent Cooperation Treaty Patent Publication WO 94/07486; Patent Cooperation Treaty Patent Publication WO 94/08583; Patent Cooperation Treaty Patent Publication WO 94/13696; U.S. Ser. No. 08/704,494, filed Aug. 20, 1996, U.S. Ser. No. 08/700,206, filed Aug. 20, 1996, and Science, 260:1640-1643 (1993).
U.S. Pat. No. 5,206,235, issued Apr. 27, 1993, describes a series of benzolactam compounds typified by the following structure. 
These compounds have demonstrated clinical activity in humans in raising the growth hormone secretory levels. B. J. Gertz, Journal of Clinical Endocrinology and Metabolism, 77:1393-1397 (1993).
Another group of growth hormone secretagogues is described in Patent Cooperation Treaty Patent Publication WO 94/13696, published Jun. 23, 1994. These compounds are typified by the following two structures. 
The present invention provides a series of compounds that have activity as growth hormone secretagogues. These compounds are non-peptidyl in nature and are, therefore, more metabolically stable than growth hormone, growth hormone releasing hormone, or analogs of either of these proteins. The compounds employed in the present invention are preferred for human pharmaceutical uses as well as veterinary uses, particularly in cattle, swine, sheep, poultry and fish.
The present invention relates to compounds of formula I 
wherein:
A is C1-C6alkyl, aryl, C1-C6alkylaryl, C1-C6alkyl(O)C1-C6alkylaryl, C1-C6alkyl(S)C1-C6alkylaryl, indolyl, indolinyl, thienyl, (C1-C6alkyl)thienyl, benzothienyl, benzofuranyl, naphthanyl, cyclohexyl, (C1-C6alkyl)indolyl, (C1-C6alkyl)benzothienyl, (C1-C6alkyl)naphthanyl, (C1-C6alkyl)benzofuranyl, and (C1-C6alkyl)cyclohexyl;
B is NH2, NHR1, C1-C6alkylNH2, C1-C6alkylNHR1, C1-C6alkylarylNH2, C1-C6alkylarylNHR1, C1-C6alkylcyclohexylNH2, C1-C6alkylcyclohexylNHR1, R1-piperidin-3-yl(C1-C6alkyl), R1-piperidin-2-yl(C1-C6alkyl), R1-piperidin-4-yl(C1-C6alkyl), R1-quinolin-2-yl(C1-C6alkyl), R1-(2,4-dihydroquinolin-2-yl(C1-C6alkyl), R1-isoquinolin-2-yl(C1-C6alkyl), and R1-(2,4-dihydroisoquinolin-2-yl(C1-C6alkyl);
R1 is hydrogen, C1-C6alkyl, C1-C6alkyl(OH), or C1-C6alkylidenyl(OH)R2;
R2 is C1-C6alkyl, C1-C6alkenyl, C1-C6alkyl(O)C1-C6 alkyl, C(O)O-C1-C6 alkyl, aryl, or C1-C6alkylaryl;
X is C1-C6alkylidenyl, O, S, NH, or N(C1-C6alkyl);
V is selected from the group consisting of 
xe2x80x83and 
W is S, O, NH, or CH2;
Y is N or CH;
Z is N or CH;
Yxe2x80x2 is N or CH;
Zxe2x80x2 is N or CH;
R4 and R5 are independently hydrogen, C1-C6alkyl, aryl, C1-C6alkylaryl, C(O)O(C1-C6alkyl), C(O)N(C1-C6alkyl)2, or C1-C6alkylCOR7;
R7 is hydrogen, C1-C6alkyl, pyrrolidinyl, piperidinyl, homoproline, or proline;
D is hydrogen, C1-C6alkyl, C1-C6alkyl(O)(CO)C1-C6alkyl, C1-C6alkyl(O)(CO)N(C1-C6alkyl)2, C1-C6alkylaryl, C(O)R6, C1-C6alkyl(O)R6, C1-C6alkyl(OH), C1-C6alkylC(O)R6, C1-C6alkylR6, aryl, (C1-C6alkyl)NHSO2(C1-C6alkyl), (C1-C6alkyl)NHSO2(aryl);
R6 is H, C1-C6alkyl, aryl, naphthyl, C1-C6alkylaryl, acetyl, NH2, NH(C1-C6alkyl), NH(C1-C6alkyl)O(C1-C6alkyl), NH(C1-C6alkyl)S(C1-C6alkyl), NH(C1-C6alkylidenyl)OCH3, NH(C1-C6alkyl)aryl, NH(C3-C6 cycloalkyl), NH(C1-C6alkyl)C(O)(C1-C6alkyl), NH(C1-C6alkyl)NH(C1-C6alkyl), NH(C1-C6alkyl)NH(C1-C6alkylaryl), NHSO2(C1-C6alkylaryl), NH(C1-C6alkyl)C(O)O(C1-C6alkyl), NH(naphthyl),N(C1-C6alkyl)2, N(C1-C6alkyl)(aryl), N(C1-C6alkyl)(C1-C6alkylaryl), O(C1-C6alkyl), O(aryl), O(C1-C6alkylaryl), piperidinyl, piperidinyl-C(O)NH(C1-C6alkyl), piperidinyl-C(O)NH(C1-C6alkylaryl), piperidinyl-C(O)N(C1-C6alkyl)2, piperidinyl-C(O)N(C1-C6alkyl)(aryl), pyrrolidinyl, pyrrolidinyl C(O)NH(aryl)-, pyrrolidinyl C(O)NH(C1-C6alkyl)-, pyrrolidinyl C(O)NH(C1-C6alkyl)2-, pyrrolidinyl C(O)NH(C1-C6alkylaryl)-, pyrrolidinyl C(O)NH(C1-C6alkyl)aryl-, pyrrolinyl, morpholino, hexamethyleneimino, heptamethyleneimino, quinolinyl, 2,4-dihydroquinolinyl, 1,2,3,4-tetrahydroquinolinyl, 2,4-dihydroisoquinolinyl, 1,2,3,4-tetrahydroisoquinolinyl, indolinyl, an amino acid selected from the group consisting of proline, homoproline, glycine, alanine, valine, leucine, isoleucine, tyrosine, tryptophan, phenylalanine, serine, threonine, asparagine, glutamic acid, aspartic acid, lysine, arginine, glutamine, histidine, cysteine, and methionine, or a nitrogen-containing heterocycle selected from the group consisting of 
E is hydrogen, C1-C6alkyl, C(O)C1-C6alkyl, aryl, (aryl)C(O)NR6, (aryl)(C1-C6alkyl)C(O)R6, Cl-C6alkylaryl, C(O)aryl, C1-C6 alkylC(O)aryl, naphthyl, C1-C6alkylnaphthyl, C(O)naphthyl, C1-C6alkylC(O)naphthyl, heteroaryl, C1-C6alkylheteroaryl, C(O)heteroaryl, C1-C6 alkylC(O)heteroaryl, indanyl, C1-C6alkylindanyl, C(O)indanyl, C1-C6alkylC(O)indanyl, cycloalkyl;
or D and E combine to form indanyl, fluorenyl, or cycloalkyl;
G is hydrogen, C1-C6alkyl, aryl, C1-C6alkylaryl, and C1-C6alkenyl;
J is hydrogen, C1-C6alkyl, aryl, and C1-C6alkylaryl;
L is hydrogen, C1-C6alkyl, C(O)OC1-C6alkyl, aryl, C1-C6alkylaryl, C(O)OC1-C6alkylaryl, C1-C6alkenyl, xe2x80x94F, and xe2x80x94CN, C1-C6alkyl-OH, C1-C6alkyl-O-C1-C6alkyl, C1-C6alkyl-C(O)R6;
or a pharmaceutically acceptable salt or solvate thereof.
The present invention relates to compounds of formula I 
wherein:
A is C1-C6alkylaryl, C1-C6alkyl(O)C1-C6alkylaryl, (C1-C6alkyl)indol-3yl, (C1-C6alkyl)benzothien-3yl, (C1-C6alkyl)naphthan-2yl, (C1-C6alkyl)benzofuran-3yl, and (C1-C6alkyl)cyclohexyl;
B is C1-C6alkylNHR1, C1-C6alkylarylNHR1, C1-C6alkylcyclohexylNHR1, R1-piperidin-3-yl(C1-C6alkyl), R1-piperidin-2-yl(C1-C6alkyl), R1-piperidin-4-yl(C1-C6alkyl), R1-quinolin-2-yl(C1-C6alkyl), R1-(2,4-dihydroquinolin-2-yl(C1-C6alkyl), R1-isoquinolin-2-yl(C1-C6alkyl), and R1-(2,4-dihydroisoquinolin-2-yl(C1-C6alkyl);
R1 is hydrogen, C1-C6alkyl, C1-C6alkyl (OH), or C1-C6alkylidenyl(OH)R2;
R2 is C1-C6alkyl, C1-C6alkenyl, C1-C6alkyl(O)C1-C6alkyl, C(O)Oxe2x80x94C1-C6 alkyl, aryl, or C1-C6alkylaryl;
X is C1-C6alkylidenyl, O, S, NH, or N(C1-C6alkyl);
V is a nitrogen-containing heterocycle selected from the group consisting of 
W is S, O, NH, or CH2;
Y is N or CH;
Z is N or CH;
R4 and R5 are independently hydrogen, C1-C6alkyl, aryl, C1-C6alkylaryl, C(O)O(C1-C6alkyl), C(O)N(C1-C6alkyl) 2, or C1-C6alkylCOR7;
R7 is hydrogen, C1-C6alkyl, pyrrolidinyl, piperidinyl, homoproline, or proline;
D is C(O)R6, CH2NHSO2(C1-C6alkyl), or C1-C6alkyl(OH);
R6 is NH2, NH(C1-C6alkyl), NH(C1-C6alkylidenyl)OCH3, NH(C1-C6alkyl)aryl, N(C1-C6alkyl)2, N(C1-C6alkyl)(aryl), N(C1C6alkyl)(C1-C6alkylaryl), O(C1-C6alkyl), piperidinyl or optionally substituted piperidinyl, pyrrolidinyl or optionally substituted pyrrolidinyl, pyrrolinyl or optionally substituted pyrrolinyl, morpholino, hexamethyleneimino, heptamethyleneimino, quinolinyl, 2,4-dihydroquinolinyl, isoquinolinyl, 2,4-dihydroisoquinolinyl, an amino acid selected from the group consisting of proline, homoproline, glycine, alanine, valine, leucine, isoleucine, tyrosine, tryptophan, phenylalanine, serine, threonine, asparagine, glutamic acid, aspartic acid, lysine, arginine, glutamine, histidine, cysteine, and methionine, or a nitrogen-containing heterocycle selected from the group consisting of 
E is hydrogen, C1-C6alkyl, aryl C1-C6alkylaryl, naphthyl, or C1-C6alkylnaphthyl, or a pharmaceutically acceptable salt or solvate thereof.
The present invention relates to compounds of Formula I, as follows: 
wherein
R1 is C6H5CH2OCH2xe2x80x94, C6H5(CH2)3xe2x80x94 or indol-3-ylmethyl; Y is pyrrolidin-1-yl, 4-C1-C6 alkylpiperidin-1-yl or NR2R2; R2 are each independently a C1 to C6 alkyl; R3 is 2-napthyl or phenyl para-substituted by W; W is H, F, CF3, C1-C6 alkoxy or phenyl; and R4 is H or CH3,
or a pharmaceutically acceptable salt or solvate thereof.
The present invention further relates to pharmaceutical formulations containing compounds of formula I, alone or in combination with other growth hormone secretagogue compounds, and/or in combination with suitable bone-antiresorptive agents, and the use of said compounds and/or formulations at least for the increase in endogenous levels of growth hormone in a mammal.
The present invention yet further relates to methods for the treatment or prevention of a physiological condition which may be modulated by an increase in endogenous growth hormone, which method comprises administering to an animal in need of said treatment an effective amount of a compound of formula I.
The present invention additionally relates to compounds of formula IA: 
The present invention still further relates to compounds of formula IB: 
The present invention additionally relates to compounds of formula Iaxe2x80x2: 
wherein E is as defined above.
Also provided are compounds of formula ZZ and ZZZ useful as chiral intermediates in the preparation of compounds of formula I: 
wherein E is as defined above.
The present invention still further relates to processes for the preparation of compounds of formula I.
The terms and abbreviations used in the instant examples have their normal meanings unless otherwise designated. For example xe2x80x9cxc2x0C.xe2x80x9d refers to degrees Celsius; xe2x80x9cNxe2x80x9d refers to normal or normality; xe2x80x9cmmolxe2x80x9d refers to millimole or millimoles; xe2x80x9cgxe2x80x9d refers to gram or grams; xe2x80x9cmlxe2x80x9d means milliliter or milliliters; xe2x80x9cMxe2x80x9d refers to molar or molarity; xe2x80x9cMSxe2x80x9d refers to mass spectrometry; xe2x80x9cFDMSxe2x80x9d refers to field desorption mass spectrometry; xe2x80x9cUVxe2x80x9d refers to ultraviolet spectroscopy; xe2x80x9cIRxe2x80x9d refers to infrared spectroscopy; and xe2x80x9cNMRxe2x80x9d refers to nuclear magnetic resonance spectroscopy.
As used herein, the term xe2x80x9cC1-C6 alkylxe2x80x9d refers to straight or branched, monovalent, saturated aliphatic chains of 1 to 6 carbon atoms and includes, but is not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, isopentyl, and hexyl. The term xe2x80x9cC1-C6 alkylxe2x80x9d includes within its definition the term xe2x80x9cC1-C4 alkylxe2x80x9d.
As used herein, the term xe2x80x9ccycloalkylxe2x80x9d refers to cyclized chains of 1 to 6 carbon atoms and includes, but is not limited to, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.
xe2x80x9cHaloxe2x80x9d represents chloro, fluoro, bromo or iodo.
xe2x80x9cC1-C6 alkoxyxe2x80x9d represents a straight or branched alkyl chain having from one to six carbon atoms attached to an oxygen atom. Typical C1-C6 alkoxy groups include methoxy, ethoxy, propoxy, isopropoxy, butoxy, t-butoxy, pentoxy and the like. The term xe2x80x9cC1-C6 alkoxyxe2x80x9d includes within its definition the term xe2x80x9cC1-C4 alkoxyxe2x80x9d.
xe2x80x9cC2-C6 alkanoylxe2x80x9d represents a straight or branched alkyl chain having from one to five carbon atoms attached through a carbonyl moiety. Typical C2-C6 alkanoyl groups include ethanoyl (also referred to as acetyl), propanoyl, isopropanoyl, butanoyl, t-butanoyl, pentanoyl, hexanoyl, and the like.
xe2x80x9cC1-C6 alkylidenylxe2x80x9d refers to a straight or branched, divalent, saturated aliphatic chain of one to six carbon atoms and includes, but is not limited to, methylenyl, ethylenyl, propylenyl, isopropylenyl, butylenyl, isobutylenyl, t-butylenyl, pentylenyl, isopentylenyl, hexylenyl, and the like.
The term xe2x80x9carylxe2x80x9d represents an aromatic ring or rings including phenyl, napthyl, biphenyl, and aromatic residues of 5 to 7-membered rings with 1 to 4 heteroatoms (a xe2x80x9cheteroarylxe2x80x9d), all of which may be optionally substituted with one or more substituents, including C1-C6 alkyl, xe2x80x94OC1-C6 alkyl, xe2x80x94OCF3, amide, NHamide, carboxamide, sulfonamide, NHsulfonamide, imide, hydroxy, carboxy, nitro, chloro, fluoro, tri(chloro or fluoro)methyl, cyano, and the like. The aromatic ring may be attached at any carbon atom or heteroatom which affords a stable structure. 3,4-methylenedioxyphenyl is included here.
The term xe2x80x9cheterocyclexe2x80x9d represents a stable 5- to 7-membered monocyclic or 7- to 10-membered bicyclic heterocyclic ring which is saturated or unsaturated and which consists of carbon atoms and from 1 to 4 heteroatoms selected from the group consisting of nitrogen, oxygen or sulfur, and wherein the nitrogen and sulfur heteroatoms may optionally be oxidized, and the nitrogen heteroatom may optionally be quaternized and including a bicylic group in which any of the above-defined heterocyclic rings is fused to a benzene ring. The heterocyclic ring may be attached at any heteroatom or carbon atom which affords a stable structure, and may be optionally substituted with one or more substituents selected from the group consisting of C1-C6 alkyl, xe2x80x94OC1-C6 alkyl, hydroxy, nitro, chloro, fluoro, or tri(chloro or fluoro)methyl, and the like.
The term xe2x80x9ccarboxy-protecting groupxe2x80x9d as used herein refers to substituents of the carboxy group commonly employed to block or protect the carboxy functionality while reacting other functional groups on the compound. Examples of such protecting groups include methyl, ethyl, p-nitrobenzyl, p-methylbenzyl, p-methoxybenzyl, 3,4-dimethoxybenzyl, 2,4-dimethoxybenzyl, 2,4,6-trimethoxybenzyl, 2,4,6-trimethylbenzyl, pentamethylbenzyl, 3,4-methylene-dioxybenzyl, benzhydryl, 4,4xe2x80x2-dimethoxy-benzhydryl, 2,2xe2x80x2,4,4xe2x80x2-tetramethoxybenzhydryl, t-butyl, t-amyl, trityl, 4-methoxytrityl, 4,4xe2x80x2-dimethoxytrityl, 4,4xe2x80x2,4xe2x80x3-trimethoxytrityl, 2-phenylprop-2-yl, trimethylsilyl, t-butyldimethylsilyl, phenacyl, 2,2,2-trichloroethyl, 2-(di(n-butyl)methylsilyl)ethyl, p-toluenesulfonylethyl, 4-nitrobenzylsulfonylethyl, allyl, cinnamyl, 1-(trimethylsilylmethyl)prop-1-en-3-yl, and the like. A preferred carboxy-protecting group for the practice of the present invention is methyl or ethyl. Further examples of these groups may be found in E. Haslam, supra, at Chapter 5, and T. W. Greene, et al., supra, at Chapter 5.
The term xe2x80x9camino-protecting groupxe2x80x9d as used herein refers to substituents of the amino group commonly employed to block or protect the amino functionality while reacting other functional groups on the compound. Examples of such amino-protecting groups include formyl, trityl, phthalimido, trichloroacetyl, chloroacetyl, bromoacetyl, iodoacetyl, and urethane-type blocking groups such as benzyloxycarbonyl, 4-phenylbenzyloxycarbonyl, 2-methylbenzyloxycarbonyl, 4-methoxybenzyloxycarbonyl, 4-fluorobenzyloxycarbonyl, 4-chlorobenzyloxycarbonyl, 3-chlorobenzyloxycarbonyl, 2-chlorobenzyloxycarbonyl, 2,4-dichlorobenzyloxycarbonyl, 4-bromobenzyloxycarbonyl, 3-bromobenzyloxycarbonyl, 4-nitrobenzyloxycarbonyl, 4-cyanobenzyloxycarbonyl, n-butoxycarbonyl, (NBoc) t-butoxycarbonyl, 1,1-diphenyleth-1-yloxycarbonyl, 1,1-diphenylprop-1-yloxycarbonyl, 2-phenylprop-2-yloxycarbonyl, 2-(p-toluyl)-prop-2-yloxycarbonyl, cyclopentanyloxycarbonyl, 1-methylcyclopentanyloxycarbonyl, cyclohexanyloxycarbonyl, 1-methylcyclohexanyloxycarbonyl, 2-methylcyclohexanyloxycarbonyl, 2-(4-toluylsulfonyl)-ethoxycarbonyl, 2-(methylsulfonyl)ethoxycarbonyl, 2-(triphenylphosphino)-ethoxycarbonyl, fluorenylmethoxy-carbonyl (FMOC), 2-(trimethylsilyl)ethoxycarbonyl, allyloxycarbonyl, 1-(trimethylsilylmethyl)prop-1-enyloxycarbonyl, 5-benzisoxalylmethoxycarbonyl, 4-acetoxybenzyloxycarbonyl, 2,2,2-trichloroethoxycarbonyl, 2-ethynyl-2-propoxycarbonyl, cyclopropylmethoxycarbonyl, 4-(decyloxy)benzyloxycarbonyl, isobornyloxycarbonyl, 1-piperidyloxycarbonyl; and the like; benzoylmethylsulfonyl group, 2-nitrophenylsulfenyl, diphenylphosphine oxide and like amino-protecting groups.
The amino-protecting group employed is usually not critical so long as the derivatized amino group is stable to the condition of subsequent reactions on other positions of the intermediate molecule, and may be selectively removed at the appropriate point without disrupting the remainder of the molecule including any other amino-protecting groups. A preferred amino-protecting group for the practice of the present invention is t-butoxycarbonyl (NBoc). Further examples of groups referred to by the above terms are described by E. Haslam, Protective Groups in Organic Chemistry, (J. G. W. McOmie, ed., 1973), at Chapter 2; and T. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis (1991), at Chapter 7.
The term xe2x80x9cleaving groupxe2x80x9d (Q) refers to a group of atoms that is displaced from a carbon atom by the attack of a nucleophile in a nucleophilic substitution reaction. Suitable leaving groups include bromo, chloro, and iodo, benzenesulfonyloxy, methanesulfonyloxy, and toluenesulfonyloxy. The term xe2x80x9cleaving groupxe2x80x9d (Q) includes activating groups.
The term xe2x80x9cactivating groupxe2x80x9d as used herein refers a leaving group which, when taken with the carbonyl (xe2x80x94Cxe2x95x90O) group to which it is attached, is more likely to take part in an acylation reaction than would be the case if the group were not present, as in the free acid. Such activating groups are well-known to those skilled in the art and may be, for example, succinimidoxy, phthalimidoxy, benzotriazolyloxy, azido, or xe2x80x94Oxe2x80x94COxe2x80x94(C4-C7 alkyl).
The compounds used in the method of the present invention may have one or more asymmetric centers. As a consequence of these chiral centers, the compounds of the present invention occur as racemates, mixtures of enantiomers and as individual enantiomers, as well as diastereomers and mixtures of diastereomers. All asymmetric forms, individual isomers and combinations thereof, are within the scope of the present invention.
The terms xe2x80x9cRxe2x80x9d and xe2x80x9cSxe2x80x9d are used herein as commonly used in organic chemistry to denote specific configuration of a chiral center. The term xe2x80x9cRxe2x80x9d (rectus) refers to that configuration of a chiral center with a clockwise relationship of group priorities (highest to second lowest) when viewed along the bond toward the lowest priority group. The term xe2x80x9cSxe2x80x9d (sinister) refers to that configuration of a chiral center with a counterclockwise relationship of group priorities (highest to second lowest) when viewed along the bond toward the lowest priority group. The priority of groups is based upon their atomic number (in order of decreasing atomic number). A partial list of priorities and a discussion of stereochemistry is contained in Nomenclature of Organic Compounds: Principles and Practice, (J. H. Fletcher, et al., eds., 1974) at pages 103-120.
In addition to the (R)-(S) system, the older D-L system is also used in this document to denote absolute configuration, especially with reference to amino acids. In this system, a Fischer projection formula is oriented so that the number 1 carbon of the main chain is at the top. The prefix xe2x80x9cDxe2x80x9d is used to represent the absolute configuration of the isomer in which the functional (determining) group is on the right side of the carbon atom at the chiral center and xe2x80x9cLxe2x80x9d, that of the isomer in which it is on the left.
In order to preferentially prepare one optical isomer over its enantiomer, a number of routes are available. As an example, a mixture of enantiomers may be prepared, and then the two enantiomers may be separated. A commonly employed method for the resolution of the racemic mixture (or mixture of enantiomers) into the individual enantiomers is to first convert the enantiomers to diastereomers by way of forming a salt with an optically active acid or base. These diastereomers may then be separated using differential solubility, fractional crystallization, chromatography, or the like. Further details regarding resolution of enantiomeric mixtures may be found in J. Jacques, et al., Enantiomers, Racemates, and Resolutions, (1991).
Preferred compounds of the present invention are compounds of formula I wherein:
A is 
B is 
J is H;
G is H;
X is NH;
V is 
E is 
D is xe2x80x94C(O)R6, where R6 is 1-pyrrolidinyl, 1-piperidinyl, 4-methyl-1-piperidinyl, N,N-dimethyl, 
L is H or CH3;
or a pharmaceutically acceptable salt or solvate thereof.
A preferred compound includes a compound of formula Id provided below: 
Also preferred are compounds of formula IA and IB provided hereinabove.
During any of the following synthetic sequences it may be necessary or desirable to protect sensitive or reactive groups on any of the molecules concerned. This may be achieved by employing conventional protecting groups as described, supra.
The compounds of the present invention may be prepared by a number of routes, many of which are known to those of skill in the art. The particular order of steps to be employed in the synthesis of compounds of formula I is dependent upon the compound to be synthesized, the starting material employed, and the relative lability of the various substituted moieties. Examples of such synthetic routes may be found in Schemes I through IV provided below, as well as in the Examples.
One synthetic route to compounds of the present invention is provided in Scheme I below. The compounds of formula IVxe2x80x2 and IV are commercially available, or may be prepared using techniques known in the art. A compound of formula IV may be prepared from a compound of formula IVxe2x80x2 through an intermediate acid chloride prepared by standard methods using thionyl chloride or oxalyl chloride. Treatment of the resulting acid chloride with a bromine source, such as N-bromosuccinimide, followed by quenching of the acid chloride with ethanol, results in compounds of formula IV. It is to be understood that the bromine group on the compound of formula IV may in fact be any suitable leaving group (Q), as defined herein. This preparation is provided below in Scheme IA. 
wherein R is representative of E as defined in a compound of formula I above.
The starting material further includes compounds of formula V, which are commercially available, or may be routinely synthesized using techniques readily known in the art. Compounds of formula IV may be coupled with a compound of formula V (4-nitroimidazole) by methods known in the art to generate a compound of formula IIbxe2x80x2. Suitable agents to be employed in the coupling of these compounds include the treatment of a compound of formula IV with an organic or inorganic base, followed by reaction with the bromo compound of formula IV. Standard organic bases include trialkylamines, potassium hexamethyldisilazide, lithium hexamethyldisilazide, lithium diisopropylamide, potassium carbonate, and the like. Preferred for the practice of the present invention is sodium hydride or potassium carbonate in dimethylformamide. A compound of formula IIbxe2x80x2 is then deprotected to provide a compound of formula IIb, using lithium hydroxide, although other deprotecting reagents may be employed in this reaction. Such deprotecting agents include standard saponification reagents such as sodium hydroxide, potassium hydroxide, and lithium hydroxide.
Substantially pure (R) enantiomers of compounds of formula IIb may also be synthesized by methods provided in U.S. Pat. Nos. 5,344,937 and 5,380,866, the disclosures of which are herein incorporated by reference.
A compound of formula IIb is then converted to the corresponding amide under appropriate conditions with a compound of formula VI to generate a compound of formula IIa. In general, amidation of primary or secondary amines of formula VI may be accomplished by a number of methods known in the art in which activation of the acid to form a better leaving group is the initial step. Suitable activating agents for this are also known in the art and include dicyclohexycarbodiimide (DCC), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) with hydroxybenzotriazole (HOBT), oxalyl chloride, thionyl chloride, PyBOP(copyright) (benzotriazol-1-yl-oxytripyrrolidinephosphonium hexafluorophosphate), and the like. Preferred for the practice of the present invention is hydroxybenzotriazole (HOBT). The nitro group on the resulting compound of formula IIa may then be reduced to an amino group using any suitable means, employing a suitable reducing agent. Preferred for the practice of the present invention is a catalytic reduction employing hydrogen and 5% palladium on carbon. A compound of formula II is produced by this reduction reaction.
The preferred reaction temperature range employed in these reactions is between xe2x88x9240 and 150xc2x0 C., and the most preferred range is between 10 and 40xc2x0 C. These reactions may be conveniently carried out in situ, without isolation of the particular compound after its preparation.
Examples of these reactions are provided below in Scheme I. 
wherein R is representative of E as previously defined, and R2R1N is R6 as previously defined.
A second portion of the overall synthesis of compounds of formula I is provided in Scheme II below. Representative starting material for this synthesis is a compound of formula IIIbxe2x80x2, which is a chemically-protected form of the amino acid O-serine. By chemically-protected it is meant that both the amino- and carboxy-functional groups have been suitably protected in order to facilitate further reactions with this molecule. Such protection reactions are known to those of skill in the art, and may be applied to other suitable starting materials. Intermediates of formula IIIbxe2x80x2 are commercially available, or may be prepared by standard syntheses of amino acids. Such syntheses are well known to persons of ordinary skill in the art and are described, for example, in Chemistry and Biochemistry of Amino Acids, (G. C. Chapman ed., 1985). The protected amino group may be specifically deprotected using trifluoroacetic acid and methylene chloride to allow for further reactions with this amino functional group. This deprotection reaction results in a compound of formula IIIb.
A compound of formula IIIb may then be N-acylated with an amino-protected compound of formula X to produce a compound of formula IIIaxe2x80x2. Suitable activating agents for this N-acylation reaction are known in the art and include DCC, HOBT, EDC, and oxalyl chloride. Preferred for the practice of the present invention is HOBT. Compounds of formula X are commercially available, or are readily prepared from suitable available starting materials. The protected carboxy group on the compound of formula IIIaxe2x80x2 is then selectively deprotected, typically using lithium hydroxide, to generate a compound of formula III. Compounds of formula III in which the starting material IIIbxe2x80x2 is 2-Nboc-amino-pentanoic acid methyl ester may also be prepared by the route described in Scheme II.
A compound of formula III is then coupled with a compound prepared from the reduction of IIbxe2x80x2 with hydrogen and a palladium catalyst employing a coupling reaction to generate a compound of formula Ia. Again, typical reagents for this N-acylation are known in the art, and include DCC and HOBT, which is the preferred method of coupling employed in the practice of the present invention. A compound of formula Ia is then selectively deprotected at the carboxy group, coupled at this site with a compound of formula VI, and then further deprotected at the amino group to generate a compound of formula Ia. Suitable agents for these deprotection and coupling reactions are discussed, infra, and are known in the art. Compounds of formula Ia are encompassed by formula I, and are pharmaceutically active.
The preferred reaction temperature range employed in these reactions is between xe2x88x9240 and 150xc2x0 C., and the most preferred range is between 10 and 40xc2x0 C. These reactions may be conveniently carried out in situ, without isolation of the particular compound after its preparation.
Alternatively, compounds of formula IIa can be coupled with compounds of formula III to provide intermediates which can be deprotected to give compounds of formula Ia.
Representative reactions are provided below in Scheme II. 
wherein R is E as previously defined, and R2R1N is R6 as previously defined.
An alternative synthetic scheme is provided in Scheme III below. A compound of formula VII (5-nitrobenzimidazole) is commercially available, or may be conveniently prepared using reactions known in the art. A compound of formula VII is coupled with a compound of formula IV in an alkylation reaction, using coupling agents as discussed, infra. A compound of formula VIIIxe2x80x2 is produced in which the carboxy functional group is protected. This protecting group is then removed as previously discussed, typically using lithium hydroxide, followed by coupling with a compound of formula XII. The nitro group on the resulting compound of formula VIII is then reduced, followed by coupling with a compound of formula III. The resulting compound of formula Ibxe2x80x2 is then deprotected to provide a compound of formula Ib. Compounds of formula Ib are encompassed by formula I, and are pharmaceutically active. These reactions are provided below in Scheme III. 
A still further representative synthesis of compounds of formula I is provided below in Scheme IV. Starting materials of formula IX (3-amino-nitrobenzene) are commercially available. Initially, a compound of formula IX is coupled with a compound of formula IV by means discussed previously. The resulting compound of formula XIxe2x80x2 is then deprotected, followed by coupling with a compound of formula XII to provide a compound of formula XI. A compound of formula XI is then reduced and further coupled in an N-acylation reaction with a compound of formula III. The resulting compound of formula Icxe2x80x2 is then deprotected to result in a compound of formula Ic. Conditions for these reactions have been discussed previously. Compounds of formula Ic are encompassed by formula I, and are pharmaceutically active. 
In addition to the Schemes described hereinabove, an enantiospecific protocol for the preparation of the compounds of formula I may be employed. Typically, a synthetic reaction design which maintains the chiral center present in the starting material in a desired orientation is chosen. The preferred reaction schemes are those that generally produce compounds in which greater than 95 percent of the product is the desired enantiomer. In Scheme V below, R-substituted phenyl is representative of the E substituents as provided in compounds of formula I above. 
The following discussion is directed to the reactions provided in Scheme V. Specifically, the reactions of compounds of formula I, II, and III are as provided in the discussion of Scheme I hereinabove.
A compound of formula IV may be prepared by the alkylation of a compound of formula III by standard methods using a base, such as sodium hydride, followed by treatment with an electrophile, such as methyl iodide. Preferred bases for this reaction include sodium-, lithium-, or potassium hexamethyldisilazide, lithium diisopropylamide, and sodium hydride. Preferred methylating agents include methyl halides or any methyl group with a suitable substituted leaving group, such as toslyate, mesylate, and the like.
A compound of formula V may be prepared by hydrolysis of a compound of formula IV using standard saponfication conditions known in the art. Suitable reagents for this transformation include sodium hydroxide or lithium hydroxide. The resulting carboxylic acid may be converted into the acid chloride by standard methods using thionyl chloride or, preferably, oxalyl chloride. The acid chloride may then be reacted with the lithium salt of a chiral auxiliary, such as (4R, 5S)-(+)-4-methyl-5-phenyl-2-oxazolidinone, to provide compounds of formula V and VI, which are readily separable by silica gel chromatography.
A compound of formula VII may be prepared by the removal of the chiral auxiliary under basic conditions, such as lithium hydroxide. Other reagents known in the art for removing oxazolidinone-type chiral auxiliaries may be used for this transformation. These include lithium hydroxide/hydroperoxide conditions, reduction/oxidation protocols, alkyl sulfur displacements, and transaminations.
A compound of formula VIII may be prepared from a compound of formula VII by standard methods known in the art. Formation of the acid chloride using oxalyl or thionyl chloride followed by reaction with a suitable substituted amine (NR2) provide compounds of formula VIII.
A compound of formula IX may be prepared by the reduction of a compound of formula VIII using hydrogen with palladium on carbon. Other methods known in the art which may be employed for the reduction of the nitro group include the use of tin(II)chloride, iron in an acidic solution, ferrous sulfate and aqueous alkali, activated alumina, and sodium sulfite. The resulting 4-amino imidazole compound of formula VIIa is then reacted directly with the appropriate dipeptide acid (a compound of formula IIX) under standard peptide coupling conditions involving formation of the active ester of the dipeptide followed by reaction with amine VIIa. Conditions suitable for amide formation include DCC, EDC, with HOBT. A compound of formula IIX may be prepared from the methyl ester of unnatural D-amino acids such as D-benzyloxyserine, D-tryptophan, and D-2-amino-5-phenyl-pentanoic acid and the like which are known in the art. Standard coupling protocols involving formation of the active ester of the amino acid using DCC/HOBt followed by reaction with N-Boc-aminoisobutyric acid provide dipeptide acids of formula IIX.
The Boc protecting group of a compound of formula IX may be removed under standard acidic conditions such as hydrochloric acid in acetic acid or ethyl acetate, trifluoroacetic acid, tetramethyliodosilane, aluminum chloride, sulfuric acid in dioxane, and methanesulfonic acid.
An additional method of preparing diastereomeric compounds of formula I involves the use of a chromatographic column which employs a chiral phase. An example of such a preparation may be found in Examples Part 6 as provided hereinbelow.
Preferred for the practice of the present invention are those compounds of formula I wherein the indicated stereochemistry is (R,R) at the two chiral centers. An example of this preferred stereochemistry is provided by compounds of formula IA and IB as provided hereinabove.
Two additional Schemes for providing chiral intermediates are provided hereinbelow as Schemes VA and VB. As described in Scheme VA, optically pure aryl glycine amino acids may be protected at the amino position by reaction with a suitable protecting group, such as Boc. Reaction of the Boc protected intermediate with a standard methylating agent, such as methyl iodide, may provide the corresponding phenolic methyl ether. The carboxamide may be prepared by coupling with an amine, such as dimethylamine, pyrrolidine, or 4-methyl piperidine, using standard coupling techniques. Preferred coupling agents for the invention are diethy cyanophosphorane (DECP), triethylamine and the amine at 0xc2x0 C. The Boc protecting group may be removed under standard acidic conditions, with trifluoroacetic acid being preferred. The desired 4-nitroimidazole compounds can be prepared by reaction of the free amine with 1,4-dinitroimidazole to give optically pure compounds, as determined by chiral HPLC. Such chiral intermediates can be processed as described in Schemes I and II to provide diastereomerically pure products. For example, the chiral nitroimidazoles described in Scheme VA or VB maybe reduced under standard conditions, such as hydrogenation with a palladium catalyst, to provide the corresponding chiral amino intermediate II. Such intermediates may be subsequently coupled with compounds of type III as previously described to provide a chiral intermediate which can be deprotected to give diastereomerically pure compounds of formula Ia. 
An additional approach and corresponding synthetic scheme for the preparation of compounds of the instant invention is provided below in Scheme VI: 
Pharmaceutically active compounds of formula I include at least compounds of formula IA, IB, Id, and Iaxe2x80x2 as described herein.
Compounds of formula I may be conveniently screened for growth hormone secretagogue activity. A typical assay may employ pituitary cells established in culture, followed by a challenge with the various compounds of formula I, and the levels of growth hormone determined accordingly. Growth hormone levels may be calculated using various radioimmunoassay techniques known to those of skill in the art. Screening of compounds for growth hormone secretagogue activity may conveniently be scaled up for high throughput screening.
The invention further encompasses methods employing the pharmaceutically acceptable salts of the compounds defined by formula I. Although generally neutral, a compound of this invention can possess a sufficiently acidic, a sufficiently basic, or both functional groups, and accordingly react with any of a number of inorganic bases, and inorganic and organic acids, to form a pharmaceutically acceptable salt.
The term xe2x80x9cpharmaceutically acceptable saltxe2x80x9d as used herein refers to salts of the compounds of formula I which are substantially non-toxic to living organisms. Typical pharmaceutically acceptable salts include those salts prepared by reaction of the compounds of the present invention with a pharmaceutically acceptable mineral or organic acid or an inorganic base. Such salts are known as acid addition and base addition salts.
Acids commonly employed to form acid addition salts are inorganic acids such as hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, phosphoric acid, and the like, and organic acids such as p-toluenesulfonic, methanesulfonic acid, oxalic acid, p-bromophenylsulfonic acid, carbonic acid, succinic acid, citric acid, benzoic acid, acetic acid, and the like. Examples of such pharmaceutically acceptable salts are the sulfate, pyrosulfate, bisulfate, sulfite, bisulfite, phosphate, monohydrogenphosphate, dihydrogenphosphate, metaphosphate, pyrophosphate, chloride, bromide, iodide, acetate, propionate, decanoate, caprylate, acrylate, formate, isobutyrate, caproate, heptanoate, propiolate, oxalate, malonate, succinate, suberate, sebacate, fumarate, maleate, butyne-1,4-dioate, hexyne-1,6-dioate, benzoate, chlorobenzoate, methylbenzoate, dinitrobenzoate, hydroxybenzoate, methoxybenzoate, phthalate, sulfonate, xylenesulfonate, phenylacetate, phenylpropionate, phenylbutyrate, citrate, lactate, xcex3-hydroxybutyrate, glycollate, tartrate, methanesulfonate, propanesulfonate, naphthalene-1-sulfonate, naphthalene-2-sulfonate, mandelate, mesylate, and the like. Preferred pharmaceutically acceptable acid addition salts are those formed with mineral acids such as hydrochloric acid and hydrobromic acid, and those formed with organic acids such as maleic acid and methanesulfonic acid.
Salts of amine groups may also comprise quaternary ammonium salts in which the amino nitrogen carries a suitable organic group such as an alkyl, alkenyl, alkynyl, or aralkyl moiety.
Base addition salts include those derived from inorganic bases, such as ammonium or alkali or alkaline earth metal hydroxides, carbonates, bicarbonates, and the like. Such bases useful in preparing the salts of this invention thus include sodium hydroxide, potassium hydroxide, ammonium hydroxide, potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, calcium hydroxide, calcium carbonate, and the like. The potassium and sodium salt forms are particularly preferred.
It should be recognized that the particular counterion forming a part of any salt of this invention is not of a critical nature, so long as the salt as a whole is pharmacologically acceptable and as long as the counterion does not contribute undesired qualities to the salt as a whole.
This invention further encompasses methods employing pharmaceutically acceptable solvates of the compounds of Formula I. Many of the formula I compounds can combine with solvents such as water, methanol, ethanol and acetonitrile to form pharmaceutically acceptable solvates such as the corresponding hydrate, methanolate, ethanolate and acetonitrilate.
This invention also encompasses methods employing the pharmaceutically acceptable prodrugs of the compounds of formula I. A prodrug is a drug which has been chemically modified and may be biologically inactive at its site of action, but which may be degraded or modified by one or more enzymatic or other in vivo processes to the parent bioactive form. This prodrug should have a different pharmacokinetic profile than the parent, enabling easier absorption across the mucosal epithelium, better salt formation or solubility, or improved systemic stability (an increase in plasma half-life, for example).
Typically, such chemical modifications include:
1) ester or amide derivatives which may be cleaved by esterases or lipases;
2) peptides which may be recognized by specific or nonspecific proteases; or
3) derivatives that accumulate at a site of action through membrane selection of a prodrug form or a modified prodrug form; or any combination of 1 to 3, supra. Conventional procedures for the selection and preparation of suitable prodrug derivatives are described, for example, in H, Bundgaard, Design of Prodrugs, (1985).
As used herein, the term xe2x80x9ceffective amountxe2x80x9d means an amount of compound of the instant invention which is capable of inhibiting, alleviating, ameliorating, treating, or preventing further symptoms in mammals, including humans, which may be due to decreased levels of endogenous growth hormone.
By xe2x80x9cpharmaceutically acceptable formulationxe2x80x9d it is meant that the carrier, diluent, excipients and salt must be compatible with the active ingredient (a compound of formula I) of the formulation, and not be deleterious to the recipient thereof. Pharmaceutical formulations can be prepared by procedures known in the art. For example, the compounds of this invention can be formulated with common excipients, diluents, or carriers, and formed into tablets, capsules, and the like. Examples of excipients, diluents, and carriers that are suitable for such formulations include the following: fillers and extenders such as starch, sugars, mannitol, and silicic derivatives; binding agents such as carboxymethyl cellulose and other cellulose derivatives, alginates, gelatin, and polyvinyl pyrrolidone; moisturizing agents such as glycerol; disintegrating agents such as agar agar, calcium carbonate, and sodium bicarbonate; agents for retarding dissolution such as paraffin; resorption accelerators such as quaternary ammonium compounds; surface active agents such as cetyl alcohol, glycerol monostearate; adsorptive carriers such as kaolin and bentonite; and lubricants such as talc, calcium and magnesium stearate and solid polyethylene glycols. Final pharmaceutical forms may be: pills, tablets, powders, lozenges, syrups, aerosols, saches, cachets, elixirs, suspensions, emulsions, ointments, suppositories, sterile injectable solutions, or sterile packaged powders, and the like, depending on the type of excipient used.
Additionally, the compounds of this invention are well suited to formulation as sustained release dosage forms. The formulations can also be so constituted that they release the active ingredient only or preferably in a particular part of the intestinal tract, possibly over a period of time. Such formulations would involve coatings, envelopes, or protective matrices which may be made from polymeric substances or waxes.
The particular dosage, of a compound required to treat, inhibit, or prevent the symptoms and/or disease of congestive heart failure in a mammal, including humans, according to this invention will depend upon the particular disease, symptoms, and severity. Dosage, routes of administration, and frequency of dosing is best decided by the attending physician. Generally, accepted and effective doses will be from 15 mg to 1000 mg, and more typically from 15 mg to 80 mg. Such dosages will be administered to a patient in need of treatment from one to three times each day or as often as needed for efficacy.
In addition, the growth hormone secretagogue compounds as disclosed herein may be administered to a patient in need of treatment in combination with other growth hormone secretagogues known in the art, and/or with a suitable bone anti-resorptive agent or agents for the prevention or treatment of osteoporosis and/or loss of muscle strength. Said suitable bone anti-resorptive agents include selective estrogen receptor modulators, bisphophonates, calcitonin, and hormone replacement therapeutic agents. Additionally, PTH may be administered in combination with said growth hormone secretagogues. Said combination therapy may be administered concomitantly or sequentially.
Suitable dosing ranges of compounds of formula I include 0.01 xcexcg/kg/day to 60 mg/kg/day.
The present invention also relates to methods for the modulation of cardiac function which comprise the administration of a compound of Formula I.
The present invention further relates to methods for the treatment or prevention of congestive heart failure by administering, to an animal in need thereof, an effective amount of a compound of Formula I.
The present invention additionally relates to pharmaceutical formulations containing a growth hormone secretagogue alone or in combination with additional therapeutic agents useful for the treatment or prevention of congestive heart failure.
The use of growth hormone secretagogue compounds, for the modulation of cardiac function and for the treatment or prevention of congestive heart failure, are described in copending U.S. patent application Ser. No. 09/137,255, filed Aug. 19, 1998, titled xe2x80x9cTreatment of Congestive Heart Failure With Growth Hormone Secretagoguesxe2x80x9d, the teachings of which are incorporated herein in their entirety by reference.
The particular dosage of a compound required to treat, inhibit, or prevent the symptoms and/or disease of congestive heart failure in a mammal, including humans, according to this invention will depend upon the particular disease, symptoms, and severity. Dosage, routes of administration, and frequency of dosing is best decided by the attending physician. Generally, accepted and effective doses will be from 15 mg to 1000 mg, and more typically from 15 mg to 80 mg. Such dosages will be administered to a patient in need of treatment from one to three times each day or as often as needed for efficacy.
Representative pharmaceutical formulations containing compounds of formula I are provided below. The formulations which follow are given for purposes of illustration and are not intended to be limiting in any way. The total, active ingredients in such formulations comprises from 0.1% to 99.9% by weight of the formulation. The term xe2x80x9cactive ingredientxe2x80x9d means a compound of Formula I.
Hard gelatin capsules containing the following ingredients are prepared:
The above ingredients are mixed and filled into hard gelatin capsules in 340 mg quantities.
A tablet formula is prepared using the ingredients below:
The components are blended and compressed to form tablets, each weighing 240 mg.
A dry powder inhaler formulation is prepared containing the following components:
The active mixture is mixed with the lactose and the mixture is added to a dry powder inhaling appliance.
Tablets, each containing 30 mg of active ingredient, are prepared as follows:
The active ingredient, starch and cellulose are passed through a No. 20 mesh U.S. sieve and mixed thoroughly. The solution of polyvinylpyrrolidone is mixed with the resultant powders, which are then passed through a 16 mesh U.S. sieve. The granules so produced are dried at 50-60xc2x0 C. and passed through a 16 mesh U.S. sieve. The sodium carboxymethyl starch, magnesium stearate, and talc, previously passed through a No. 30 mesh U.S. sieve, are then added to the granules which, after mixing, are compressed on a tablet machine to yield tablets each weighing 120 mg.
Capsules, each containing 40 mg of medicament are made as follows:
The active ingredient, cellulose, starch, and magnesium stearate are blended, passed through a No. 20 mesh U.S. sieve, and filled into hard gelatin capsules in 150 mg quantities.
Suppositories, each containing 25 mg of active ingredient are made as follows:
The active ingredient is passed through a No. 60 mesh U.S. sieve and suspended in the saturated fatty acid glycerides previously melted using the minimum heat necessary. The mixture is then poured into a suppository mold of nominal 2.0 g capacity and allowed to cool.
Suspensions, each containing 50 mg of medicament per 5.0 ml dose are made as follows:
The medicament, sucrose and xanthan gum are blended, passed through a No. 10 mesh U.S. sieve, and then mixed with a previously made solution of the microcrystalline cellulose and sodium carboxymethyl cellulose in water. The sodium benzoate, flavor, and color are diluted with some of the water and added with stirring. Sufficient water is then added to produce the required volume.
Capsules, each containing 15 mg of medicament, are made as follows:
The active ingredient, cellulose, starch, and magnesium stearate are blended, passed through a No. 20 mesh U.S. sieve, and filled into hard gelatin capsules in 425 mg quantities.
An intravenous formulation may be prepared as follows:
A topical formulation maybe prepared as follows:
The white soft paraffin is heated until molten. The liquid paraffin and emulsifying wax are incorporated and stirred until dissolved. The active ingredient is added and stirring is continued until dispersed. The mixture is then cooled until solid.
Sublingual or buccal tablets, each containing 10 mg of active ingredient, may be prepared as follows:
The glycerol, water, sodium citrate, polyvinyl alcohol, and polyvinylpyrrolidone are admixed together by continuous stirring and maintaining the temperature at about 90xc2x0 C. When the polymers have gone into solution, the solution is cooled to about 50-55xc2x0 C. and the medicament is slowly admixed. The homogenous mixture is poured into forms made of an inert material to produce a drug-containing diffusion matrix having a thickness of about 2-4 mm. This diffusion matrix is then cut to form individual tablets having the appropriate size.
Another formulation employed in the methods of the present invention employs transdermal delivery devices or patches. Such transdermal patches may be used to provide continuous or discontinuous infusion of the compounds of the present invention in controlled amounts. The construction and use of transdermal patches for the delivery of pharmaceutical agents is well known in the art. See, for example, U.S. Pat. No. 5,023,252, the disclosure of which is herein incorporated by reference. Such patches may be constructed for continuous, pulsatile, or on demand delivery of pharmaceutical agents.
Frequently, it will be desirable or necessary to introduce the pharmaceutical composition to the brain, either directly or indirectly. Direct techniques usually involve placement of a drug delivery catheter into the host""s ventricular system to bypass the blood-brain barrier. One such implantable delivery system, used for the transport of biological factors to specific anatomical regions of the body, is described in U.S. Pat. No. 5,011,472, the disclosure of which is herein incorporated by reference.
Indirect techniques, which are generally preferred, usually involve formulating the compositions to provide for drug latentiation by the conversion of hydrophilic drugs into lipid-soluble drugs or prodrugs. Latentiation is generally achieved through blocking of the hydroxy, carbonyl, sulfate, and primary amine groups present on the drug to render the drug more lipid soluble and amenable to transportation across the blood-brain barrier. Alternatively, the delivery of hydrophilic drugs may be enhanced by intra-arterial infusion of hypertonic solutions which can transiently open the blood-brain barrier.